<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="../react18/react.development.js"></script>
  <script src="../react18/react-dom.development.js"></script>
  <script src="../react18/babel.min.js"></script>
  <script src="../react18/prop-types.js"></script>
</head>

<body>
  <div id="app"></div>
  <script type="text/babel">

    class App extends React.Component{
      constructor(){
        super()
        let {opacity} = this.state;
        setInterval(()=>{
          opacity -= 0.1;
          if(opacity <= 0){
            opacity =1
          }
          this.setState({opacity})
        },100)
      }

      state = {
        opacity : 1
      }

      render(){ 
        let {opacity} = this.state;
        return (
          <div>
            <h1 style={{opacity}}>React真难啊</h1>
            <button onClick={this.handle}>不学了 我学vue去了</button>  
          </div>
        )
      }

      handle = () => {
        root.unmount();
      }
    }

    const root = ReactDOM.createRoot(document.getElementById('app'));
    root.render(<App/>)

  </script>
</body>

</html>